This invention provides a key step for the automation of the garment industry by the elimination of the need for manual pickup and handling of individual fabric layers. The invention has particular application to the separation of textile layers from a stack where the nature of the textile fabric may be different from one layer to the next.
For many decades the step of manual pickup has been a chief obstacle to automated manufacture of garments. It has long been possible to efficiently form a stack of identically shaped component pieces for a garment by simultaneous cutting with a fabric saw through a multiplicity of overlying layers, guided by a pattern. Likewise, accurate sewing together of the various components has been effciently accomplished as by use of automated platens and high speed sewing machines. The possibility of computer control in recent years has increased the speed of such techniques that already had been quite fast.
But between the steps of forming the stack and sewing together the individual pieces there has remained the tedious manual step of picking up individual pieces from a stack or other surface. The threads at the cut edges of the pieces, the limpness of the pieces, and the variation in their texture and other parameters from piece to piece, have together made the separation problem one of the chief obstacles to elimination of the slowness and expense of manual labor in the garment industry.
Our own work on this problem for more than a quarter of a century, as well as the work of numerous others, is testimony to the difficulties of the problem. Although we and others have been able to find ways to separate like pieces, and to show promising progress even with dissimilar pieces, the proposed solutions of the past work of ourselves and others have not been found acceptable by the industry.
Our prior designs are shown in U.S. Pats. Nos:
3,168,307, Walton et al, 1962; PA1 3,369,803, Walton et al, 1968; PA1 3,406,961, Walton, 1968; PA1 3,406,966, Walton, 1968; PA1 3,531,103, Walton, 1970; PA1 3,813,094, Walton et al, 1974. PA1 793,009, Miller, 1903; PA1 1,649,319, Molyneux, 1927; PA1 1,708,195, Kinney, 1930; PA1 3,026,109, Pfeffer, 1962; PA1 3,176,979, Engelmann, 1965; PA1 3,291,480, Haddad, 1966; PA1 3,253,824, Southwell et al, 1966; PA1 3,353,821, Smith et al, 1967; PA1 3,386,396, Jacobs et al, 1968; PA1 3,386,763, Ottaway et al, 1968; PA1 3,442,505, Szentkuti, 1969; PA1 3,547,432, Herdeg, 1970; PA1 3,550,932, Mason, 1970; PA1 3,583,695, Sherwood, 1971; PA1 3,588,091, Stone et al, 1971; PA1 3,625,506, Rosin, 1971; PA1 3,747,919, Stewart et al, 1973; PA1 3,756,587, Lutts et al, 1973; PA1 3,806,114, Carter, 1974.
Examples of the work of others in the same or somewhat related fields are U.S. Pat. Nos.:
This corpus of work represents an extensive, long term, diligent effort at use of needles and other gripping materials, tensioning and nipping motions, and air and vacuum assists, etc., aimed at this seemingly simple problem. Yet, the garment industry continues to move to those places in the world where manual labor can be afforded at lowest cost, one major reason being the need, as still recognized, to use hand dexterity for picking up and performing related operations on individual fabric pieces.